1. Technical Field
The present invention relates to an electromagnetic oscillating type pump and a method for manufacturing the same. More particularly, the present invention relates to an electromagnetic oscillating type pump which is mainly utilized for suction and discharge of air of indoor type air mattresses or airbeds, for supplying oxygen to fish-farming aquariums or purifying tanks for domestic use as well as for sampling gas for examination purposes in monitoring pollution.
2. Discussion of the Related Art
An example of a conventionally known electromagnetic oscillating type pump is a diaphragm type pump as illustrated in FIG. 39 which utilizes magnetic interaction between electromagnets and permanent magnets wherein suction and discharge of fluid is performed by utilizing oscillating force of an oscillator provided with such permanent magnets.
This pump comprises an electromagnetic portion composed of electromagnets 151 disposed as to oppose each other, an oscillator 153 having permanent magnets 152, diaphragms 154 connected to both ends of the oscillator 153, diaphragm bases 154a and pump casings 155 respectively fixed to both end sides of the electromagnetic portion, and a pump compressing chamber 156 formed between the diaphragm 154 and the pump casing 155. Each electromagnet 151 is assembled by installing a wound coil portion 158 around an E-shaped iron core 157, and the oscillator 153 is disposed in a clearance portion 159 formed between the iron cores 157.
Suction and discharge of air is performed in an alternating manner on the right and left of the pump, being affected by changes in capacity of the pump compressing chamber 156 to increase and decrease contrarily on the right and left owing to oscillation of the oscillator 153 supported by the diaphragms 154.
However, there is presented a drawback with such a conventional type pump that it is difficult to secure a specified dimension for the clearance portion at the time of assembling the electromagnetic portion since specified positions for the iron cores are shifted. It is also quite costly when housing the pump in a separate sound isolating case to insulate noise arising from the pump portions. It is also difficult to improve productivity since three parts, namely the electromagnetic portion, the diaphragm base and the pump casing, need to be assembled.
An alternative pump is a pump as illustrated in FIG. 40 comprising two sets of casings 203, 204 for supporting a diaphragm 201 while forming a pump chamber 202, an oscillator 205 connected to the diaphragm 201, an electromagnetic portion 207 comprising electromagnets 206, a filter holding portion 208, and an air tank 209. A cylindrical body 210 is attached between the casings 203, 204 by means of screws 210-a, and a pump main body 211 is formed by accommodating the electromagnetic portion 2097 in the cylindrical body. The pump main body 211 is accommodated in a housing 212 with the filter holding portion 208 being fitted into an upper portion of the housing 212 with the filter holing portion 208 being fitted into an upper portion of the housing 212 while the air tank 209 is attached to its lower portion by means of screws 212a. 
This pump also utilizes forced oscillation of the diaphragm 201 so that the pump main body 211 itself is oscillated and thus generates a large noise. Therefore, it has been devised to support the pump main body 211 at the air tank 209 through four stepped cushions 213 to thereby absorb oscillation within the housing 212.
However, this arrangement of making the pump main body 211 be supported at the air tank 209 by the four stepped cushions 213 makes it troublesome to mount the pump main body 211, and it is still difficult to satisfactorily absorb the oscillation. There are further presented drawbacks that the housing 212 becomes large-sized in contrast to the pump main body, and that it is difficult to reduce manufacturing cost because the cost for the housing is most expensive among utilized parts.
The present invention has been made in view of the above facts, and it is an object thereof to provide an electromagnetic oscillating type pump exhibiting high acoustic insulating effects while reducing manufacturing costs.